Typically, in electroetching or electroplating a fixture is used to hold a workpiece such as a semiconductor wafer in a bath. The fixture is connected to a power source, and contacts the workpiece to make it either the cathode or anode, depending on whether etching or plating is desired.
Depending on the size and shape of the workpiece, there will be several to many electrical contacts to the workpiece. The failure of just one contact can result in a defective workpiece, as the workpiece will not be properly charged across the entire surface for processing. In the case of semiconductor processing, the loss of just one wafer can be very expensive, depending on how much processing has been completed.
The testing of contacts is tedious and often impractical, and requires disconnection and disassembly of the fixture to isolate individual contacts for contact resistance measurement. Thus, there remains a need for electroprocessing contact testing without fixture disassembly, and preferably one that can be performed in-situ (while the fixture contains a workpiece). Therefore any contact failures could be immediately identified and corrected before scrapping any workpieces.